feat(cli): port ghostty +action CLI commands

Ports ZIG/src/cli into ghostty-cli: action detection/dispatch with
per-action --help, and the actions help, version, list-actions,
list-colors, list-keybinds, list-themes (plain listing plus an
interactive ratatui browser mirroring Ghostty's libvaxis UI),
show-config, validate-config, edit-config, crash-report (listing),
ssh-cache and boo (235 embedded frames).

Verified byte-for-byte against the installed Ghostty 1.3.1 for stdout,
stderr and exit codes of most actions, incl. tty output in a pty at
widths 20-200. Known differences: +list-colors --plain prints all 782
colors (Ghostty truncates at 617 because it never flushes), +version
has placeholder build info until build_info::set is wired up.

Deferred: list-fonts, show-face (need font discovery integration) and
new-window (needs GTK IPC); they return NotYetAvailable for now.

Test Plan:
- cargo test -p ghostty-cli (86 tests)
- cargo run -p ghostty-cli --example cli -- +list-keybinds --plain
  and diff against `ghostty +list-keybinds --plain`

crates/ghostty-cli/src/list_fonts.rs

@@ -0,0 +1,57 @@
+//! `+list-fonts` (ZIG/src/cli/list_fonts.zig).
+//!
+//! DEFERRED: needs the font crate (font discovery). Only the options and
+//! help are ported; running the action reports that it is not available.
+
+use ghostty_config::config_struct;
+
+use crate::error::Error;
+
+config_struct! {
+    pub struct Options {
+        /// The font family to search for. If this is set, then only fonts
+        /// matching this family will be listed.
+        "family" => family: Option<String> = None,
+
+        /// The style name to search for.
+        "style" => style: Option<String> = None,
+
+        /// Font styles to search for. If this is set, then only fonts that
+        /// match the given styles will be listed.
+        "bold" => bold: bool = false,
+        "italic" => italic: bool = false,
+    }
+}
+cli_options!(Options, help);
+
+/// The `list-fonts` command is used to list all the available fonts for
+/// Ghostty. This uses the exact same font discovery mechanism Ghostty uses to
+/// find fonts to use.
+///
+/// When executed with no arguments, this will list all available fonts, sorted
+/// by family name, then font name. If a family name is given with `--family`,
+/// the sorting will be disabled and the results instead will be shown in the
+/// same priority order Ghostty would use to pick a font.
+///
+/// Flags:
+///
+///   * `--bold`: Filter results to specific bold styles. It is not guaranteed
+///     that only those styles are returned. They are only prioritized.
+///
+///   * `--italic`: Filter results to specific italic styles. It is not guaranteed
+///     that only those styles are returned. They are only prioritized.
+///
+///   * `--style`: Filter results based on the style string advertised by a font.
+///     It is not guaranteed that only those styles are returned. They are only
+///     prioritized.
+///
+///   * `--family`: Filter results to a specific font family. The family handling
+///     is identical to the `font-family` set of Ghostty configuration values, so
+///     this can be used to debug why your desired font may not be loading.
+pub fn run(args: &[String]) -> Result<u8, Error> {
+    let mut opts = Options::default();
+    crate::parse_options(&mut opts, args)?;
+
+    // TODO(integration): port the discovery/listing once ghostty-font lands.
+    Err(Error::NotYetAvailable("list-fonts"))
+}